The compound of formula(I)is a water-stable, long acting β2-selective adrenoceptor agonist useful as a bronchodilator in the treatment of bronchoconstriction associated with reversible obstructive airways diseases and the like.式(I)化合物是一種有用於在與可逆性呼吸道阻塞疾病以及類似者有關的支氣管收縮治療中作為支氣管擴張劑之耐水、長效的β2-選擇性腎上腺素受體促效劑。